[RAIIIJudge]

hi, fellas',

was installing a new balancer, which went on ezpz w/o "installer" and I didn't use bolt to run it in. the bolt that was originally in there was longer than correct which got my attention. I ran a brand new, correct bolt and washer in w/ my fingers,
it seemed to grab ok. I started torquing balancer on incrementally .. I got up to 150 ft lbs when threads just let loose, gone. obviously this is a big kick in the nuts.

I've reached out to some pro's who've said motor has got to come out and crank replaced .. one shop said "repaired" and added that guys that have skills required are tough to find.

A local guy whose garage has been in the family for 60+ years and who has a 67 Goat says if it were his car no way he'd pull motor that he'd install a sleeve.

If I were to pull motor where would it end? The assembly that's there was balanced. What are the implications there if I were to put a new crank in? What bearing would get replaced w/ this option?

I looked at inserts a little and I plan to call some manufacturers. Crank threads get enlarged to accommodate the 5/8 18 insert (can get in .850 or 1.25" length) which is installed w/ red Loctite on its outside. Not sure if it's the installer tool or the crank bolt that expands insert sleeve to further seat it. I'd have to spring for $275 tool and $60 for inserts.

Thanks in advance for your thoughts,
Mike
MA

[JSchmitz]

Are you sure you have the right length bolt? Have you looked inside the crank snout to see how many threads are left, damaged, etc.? Could you cut the long bolt down to grab the threads that are left? For full strength, you need 1-1/2 the fastener diameter in threads.

[RAIIIJudge]

I'll double check but I have a clean, correct OEM bolt/washer + an Inline .. neither stay put when torqued at all.
See pics please
Also, I recall reading at snout and required torque I need 3/4" minimum?

[Half-Inch Stud]

I probably have a Longer Balancer Bolt, an oddity that i kept. Drill and tap deeper. Might even have the tap.

[Formulas]

No guarantees with this approach but you could try to run a bottoming tap in to possibly cut some new threads deeper then reevaluate with a longer bolt to catch the new threads and some of the threads left by using the shorter bolt

Or measure the hole and see what the next size you could tap it out to either US. or metric,

I noticed a long time ago that the OE. bolt could grab more threads and I use off the shelf G8 next longer bolt just because i can

To get a rough measure of the hole now just measure the od of the threads on the bolt your using to see if the next size metric or US. will work

[grandam1979]

Try using the bolt you removed thats probably why it was used in the first place. If it doesn’t hold at this point you’re no worse off.

[Mr Twister]

Verify you have a 5/8-18 bolt. Those pics show threads that "may" clean up with a bottoming tap

[BILL BOWMAN1]

I would be interested to see the bolt, and any material it may have pulled out with it.

[chiphead]

Couldn't you have a time-sert thread repair installed in the snout of that crank?

https://www.timesert.com/

[RAIIIJudge]

fellas,

I really appreciate y'all's thoughts here, thank you!

here's a pic of (R) bolt I pulled out originally (L) new one that I installed that stripped.

I'm juggling a little bit today just on home front so I haven't gotten my head around all the possible options you guys are considering:
tapping to next size up? the distinction between tapping and starting w/ a bottoming tap?
if you read my original post you'll see where I have investigated the time-sert sleeve option.

if tapping to next larger is an option, isnt that preferable to adding a sleeve?

regardless of how badly threads are damaged I dont think there are any threads left that haven't been farked up no? ie no going w/ a longer bolt to get to "good" threads.

THANK YOU again, fellas,
mike
MA

[rwfisher]

You have to be careful when using longer bolt. If it is long enough that it bottoms out and you try to torque it you will pull out any remaining thread on the crank..

[PAUL K]

If all else fails you could use an aftermarket hone to fit damper. If fit properly you could run the balancer without a bolt.

[Formulas]

if you were using the longer bolt with that small washer iam not so sure the bolt was actually holding the damper on

the large stock washer barely goes out far enough to catch the damper itself

[RAIIIJudge]

there was another second washer that was the correct diameter but a lot thinner, originally on the longer bolt ..
sorry, that got left out of picture.

I think, bottom line, all of the crank threads are compromised.

[chiphead]

A properly installed threaded insert will be just as strong as the original threads. My first thought would be to install a heli-coil yourself. The professional machinists here can comment if a heli-coil would hold 160 ft/lbs. The next option is the time-cert, which I'm sure will hold the torque. Again you can install yourself or have a shop do it.

If this was me, I'd see if a mag-drill could be used to drill the hole accurately without removing engine from car. Then you could tap the crank snout for the threaded insert of your choice.

[70pontiaction]

As much as a pain as it will be, I'd be taking the engine out and sourcing a replacement crankshaft.

This could be your excuse to spend the $$ on a forged steel crankshaft and rods. Unless you already upgraded the rods, then it's just a stronger crank.

More money now, but no headaches / questions / worries about it later on.

Good luck!

[Mr Twister]

I wonder how many dampers with stripped crank threads just got stick welded on back in the day. You know, back when there was a guy down the street with a welder and no one had any money. haha

[johnta1]

Take a machinist ruler and stick it in the hole to see how deep it actually is.
Then compare it to the bolt. I have seen there is a lot of threads left in there.

I have also used a stud in there with locktite. Use a nut to hold balancer on.

[mgarblik]

I think I have good news for you. This is an easy on the car fix. I will provide a link at the end. Just go to a NAPA store and buy a 5/8-18 Heli-coil kit. $63.00 Also you will need the drill bit size listed in the kit. Probably $10.00. Pack a paper towel around the crank and front seal so you don't get chips in the engine. Drill, tap and install the heli-coil. Install a brand new bolt. The ones in your pics both have damaged threads. Torque to specs" 160 Ft. Lbs. and your done. It's a 1/2 hour to 45 minute job. Easy, reliable, just as good as new. Good luck: https://www.napaonline.com/en/p/BK_7703087

[mgarblik]

I think I have good news for you. This is an easy on the car fix. I will provide a link at the end. Just go to a NAPA store and buy a 5/8-18 Heli-coil kit. $63.00 Also you will need the drill bit size listed in the kit. Probably $10.00. Pack a paper towel around the crank and front seal so you don't get chips in the engine. Drill, tap and install the heli-coil. Install a brand new bolt. The ones in your pics both have damaged threads. Torque to specs" 160 Ft. Lbs. and your done. It's a 1/2 hour to 45 minute job. Easy, reliable, just as good as new. Good luck: https://www.napaonline.com/en/p/BK_7703087